Authorities in Bahrain have detained opposition leaders, after security forces drove pro-democracy protesters out of a main square in the capital.

A statement read on Bahrain's state television said authorities had arrested "several" leaders on charges that include communicating with foreign countries.

Opposition members said Thursday that the government has detained at least six opposition leaders since clearing the protesters' tent camp from Manama's Pearl Roundabout on Wednesday. They said the detainees include Hassan Mushaima of the Haq movement, Wa'ad party leader Ibrahim Sharif and Shi'ite activist Abdul Wahad Hussein.

At least five people were killed Wednesday when Bahraini security forces swept through the square, which had been a rallying point for protesters.

The Associated Press says riot police on Thursday fired tear gas at several dozen protesters who tried to regroup near Manama.

Bahrain's government declared a three-month state of emergency on Tuesday as part of efforts to end a month of protests. However, a military spokesman announced on Thursday that a 12-hour evening and overnight curfew would be shortened by four hours in parts of the capital.

Protesters from Bahrain's majority Shi'ite population are demanding political reforms from the minority Sunni government.

The ruling al-Khalifa family has offered to hold a dialogue with opposition groups. But some protesters are demanding more power for parliament and that the royal family be ousted.

On Monday, King Hamad bin Isa al-Khalifa authorized about 1,000 Saudi soldiers and 500 United Arab Emirates' police to enter Bahrain to protect government buildings after groups of protesters paralyzed the capital's financial district.